This invention relates to a pressure responsive sealing assembly for containing pressurized fluids within a region formed between the inner and outer casings of a high pressure rotary-type machine.
A barrel-type machine configuration has been developed suitable for accommodating increasing pressures demanded on rotary-type machines. This concept has been widely employed in the centrifugal compressor art. In a barrel-type compressor, an inner casing is mounted within an outer casing. The outer casing is generally constructed of a single-piece, open-sided cylinder which is well suited to withstand the relatively high pressures involved. The inner casing is divided into two sections that are arranged to part along the axial centerline of the machine shaft. In assembly, the stationary machine components are supported within the inner casing and the casing then closed about the rotor structure. The inner casing assembly is next inserted into the outer casing and the machine enclosed by means of conventional end walls or the like. A chamber is provided between the two casing sections. The low pressure end of the chamber is sealed and high pressure working fluids developed within the machine are allowed to enter the chamber region from the high pressure side of the machine. Pressurizing the chamber in this manner serves to firmly seat the inner assembly within the outer casing and also securely holds the two halves of the inner casing tightly in place. Proper positioning of the casing seal during assembly and maintaining the integrity of the seal under operating loads has long been a problem in the art.